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Sizing up the microscopic: research voyage sets sail to gauge the magnitude of the plastic problem

19 September 2016

Researchers from PML and the National Oceanography Centre (NOC) embark this week on the collaborative annual research cruise Atlantic Meridional Transect (AMT) programme, where, amongst other projects, they aim to further understand how tiny pieces of plastic litter are affecting the open ocean and life within.

The UK government’s plan to ban microbeads used in cosmetic and cleaning products next year comes off the back of years of research by UK scientists. While this proposed ban aims to reduce levels of microplastics (degraded or manufactured plastic less than 5mm in size) in the ocean, future work to be undertaken by PML and NOC scientists on board the 26th AMT voyage will address a number of key questions which remain; how much microplastic material is present in the Atlantic ocean and what is the physical impact of such on marine life, in particular the tiny organisms at the base of the marine food web that ingest these particles.

Since 1995, the AMT voyage has undertaken annual biological, chemical and physical oceanographic research during a passage between the UK and destinations in the South Atlantic, and has included 25 research cruises involving more than 250 scientists from over 20 countries.

The 26th voyage of AMT will be the first of its kind to follow such a long transect sampling for microplastics from the North to the South Atlantic. Travelling 600 miles daily aboard the RRS James Clark Ross research vessel, scientists will be analysing data from a large number of data points, covering vast areas including the remote, desert-like gyres in the centre of both the North and South Atlantic, otherwise generally untouched by other research efforts. Studying the gyres, systems of rotating ocean currents, will help scientists determine whether these areas are collecting and containing plastics or in fact breaking them down to distribute into the wider ocean.

Madeleine Steer, Plymouth University MRes student, has for the past year being working within PML’s microplastic research group led by Dr. Penelope Lindeque. Madeleine who will be on-board the RRS James Clark Ross departing for AMT26 on the 20th September commented:

“AMT26 allows us to cover a vast distance, encompassing many different zones of both the North and South Atlantic. We expect to find the type of microplastics in the water to change as we travel through oceanic zones and with Dr Katsia Pabortsava from the NOC we will be covering a number of aspects of microplastic research. Scientists have proven zooplankton ingest microplastics and suffer adverse effects from doing so under laboratory conditions, we will be analysing ingestion rates of microplastics in zooplankton in the ocean. We’ll also be “fishing for plastics” in order to measure concentrations and characteristics of the microplastics at the surface and down to considerable depth. This is ground breaking work and addresses the next step in research that will help us understand the effect microplastics are having in the marine environment from individual organisms through to populations, communities and even whole ecosystems.”

Professor Richard Lampitt and Dr Katsia Pabortsava, who lead microplastic research at NOC, added:

“There is considerable uncertainty about the concentration and characteristics of the many different types of microplastics and how these factors change over time and space. Our work in the vast open ocean spaces, hundreds of miles from land is a crucial part of this assessment. The deep sea is considered one of the major sinks of microplastic debris and so we intend to focus part of our research in this area. The deep sea also has a huge diversity of marine life, yet we do not know how much plastic is in this part of the ocean or how it may enter food chains or affect marine life there.”

Laboratory studies as part of collaborative research between PML and the University of Exeter have shown that zooplankton suffer physiological effects from eating microplastics, from decreased reproduction, to death, which in turn could impact other species further up the food chain. Dr Lindeque comments “for the past 2 years we have been investigating the extent and impact of microplastics in coastal waters local to Plymouth. The AMT will provide a fantastic opportunity to scale our research from the western English Channel to the open ocean including both the North and South Atlantic”.

Through this research cruise scientists can continue ongoing research with aims to inform future policy and aid decision making on this topic.

The proposed government ban on microbeads only represents a very small part of a larger issue. Microbeads, including exfoliating beads and granules used in facial scrubs and shower gels, are only some of the small plastics that constitute microplastics; others microplastics include synthetic fibres that shed from clothing and fabrics, and tiny fragments that derive from larger items of plastic litter. “These fibres and plastic fragments have been found consistently in local seawater samples, the research on AMT will allow us to determine how far this problem extends. This will help us fill in knowledge gaps for future policy direction on marine pollution”, said Lindeque.

The 23rd Atlantic Meridional Transect (AMT) research cruise will be leaving Portsmouth early next week with PML scientists on-board, spending 5 weeks sailing the Atlantic to arrive in the Falklands 08 November.

The 24th Atlantic Meridional Transect (AMT) research cruise will be leaving Immingham at the end of this week with PML scientists on-board, spending 6 weeks sailing the Atlantic to arrive in the Falklands in early November.